What is the best free tool stack for prediction market trading?

The stack community roundups keep recommending: Polymarket Analytics to see who is actually winning, Polysights for AI-assisted market analysis, and Polylerts for free Telegram alerts when top wallets move. Add the free DefiRate calculator suite for fee and EV math, and a free cross-venue terminal like Kairos to trade Kalshi and Polymarket from one book.

Is there one tool that shows Kalshi and Polymarket together?

For viewing odds side by side, Oddpool and Prediction Hunt compare venues. For actually trading them together, Kairos aggregates Kalshi, Polymarket and Predict.fun into one live order book with sub-second data. No tool yet tracks your combined portfolio P&L across venues automatically; that remains the biggest gap in the landscape.

Are there good tools for Kalshi specifically?

Fewer than for Polymarket, because Kalshi trades are anonymous and its leaderboard is opt-in, which limits what third parties can build. Lychee Data covers Kalshi historical data, OddsAssist has a free Kalshi fee calculator, TrendSpider ships a Kalshi indicator suite, and cross-venue terminals like Kairos include Kalshi's full book. Treat any third-party Kalshi leaderboard with care: they are built from small opt-in pools, not the exchange's actual top traders.

Do prediction market tools cost money?

The essentials are free: venue leaderboards, DefiRate's 13 calculators, EventArb's arbitrage calculator, Polylerts alerts, Dune dashboards, and the Kairos terminal. Paid tiers cluster around copy trading ($20 to $30 a month), arbitrage scanning ($9 a week to $59 a month), and historical data (subscription pricing).

Best Prediction Market Tools (2026)

Every tracker, arb finder, calculator, alert bot and tax tool worth knowing for Polymarket and Kalshi traders, each on its own page with prices and claims verified against the live site.

Updated September 8, 2026 · 53 tools reviewed on their own pages · every price checked against the live site

Short answer: there are 170+ tools and most traders need five: Polymarket Analytics for who wins, Polylerts for alerts, DefiRate for the math, Oddpool to compare venues, and Kairos, the free a16z-backed terminal, to execute across every venue from one book.

Browse by category

7 categories

Leaderboards & whales13 tools Analytics & data11 tools Arbitrage7 tools Odds comparison4 tools Calculators6 tools News & alerts8 tools Portfolio & tax5 tools

The directory

55 tools · filter by category

Kairos Cross-venue trading terminal: Kalshi, Polymarket and Predict.fun in one order book, with sub-second data and advanced order types. K + PM + Predict.funfreea16z-backed
0xInsider Seeing which graded Polymarket wallets are on each side of a sports or esports game before kickoff, with a public pick record to audit. Polymarketfree tier$25/wk
Hashdive One of the few dual-venue trackers: Smart Score ratings, whale feed, insider detection, screeners. PM + Kalshifree
KalshiSpy Surfaces verified profitable Kalshi traders' open positions and builds a consensus view. Kalshi$61/mo
Polycopy Copy trading on a leaderboard: Copy Score net of costs, automated trader bots with stop-losses. Polymarketfree tier$30/mo + 0.5%
Polymarket Analytics 1M+ wallets ranked by P&L, win rate and streaks, refreshed every 5 minutes. The category leader. Polymarketfree$20/mo premium
Polymarket leaderboard The official profit and volume rankings, also exposed through a public API endpoint. Polymarketfree
polymarket-whales Open-source Python CLI that watches order flow and pings Telegram on threshold-size trades. PolymarketOSS
PolyWallet Tracking a handful of Polymarket wallets, yours or anyone's, with a P&L calendar and live unrealized P&L, without connecting anything. Polymarketfree tier$9.99/mo
Polywhaler A live cross-venue whale feed with an insider-risk score on every $10K+ trade and a wallet leaderboard behind it. Polymarket + Kalshifree tier$9/mo
PredictFolio Free blockchain-based trader and portfolio analytics; a reference for data accuracy. Polymarketfree
Predicts.guru A free Polymarket wallet checker: paste an address or username and read P&L, win rate, open positions and trade history. Polymarketfree
SightWhale Telegram alerts when one of Polymarket's top 1% wallets makes a sized trade, with every past signal kept on a public record. Polymarketfree tier$29/mo
WhaleScanr Following a short, statistically screened roster of Polymarket wallets and getting each of their buys with the matching Kalshi market attached. Polymarket + Kalshifree tier$19/mo
DefiRate prediction market volume tracker Daily-updated Kalshi and Polymarket volume, market share and category breakdowns with CSV export. cross-venuefree
Dune dashboards Community SQL dashboards: venue volumes, open interest and users across Polymarket, Kalshi, Limitless. cross-venuefree
Kalshi Pro Kalshi's own power-user interface: real price and volume charts, live trade-by-trade view. Kalshifree
kalshi-dash Plotting your own Kalshi PnL over time from transaction CSVs without your data leaving the browser. Kalshifree34 stars
Lychee Data The Kalshi historical answer: 36GB+ of trades and order books with no-code charting and backtesting. Kalshifree + paid
Polyanalytics Polymarket market heatmaps and wallet PnL with a Kalshi spread check and CSV export on the paid tier. Polymarket + Kalshifree tier$29
PolymarketData Historical infrastructure: minute-level prices and L2 order book snapshots, 19B+ rows, API and bulk S3. Polymarketpaid tiers
PolyScope Free 15-minute Polymarket price, spread and order book snapshots across every active market, with a downloadable historical dataset. Polymarketfree tier$92 stars
Polysights AI-assisted dashboard: market summaries, insider-activity signals, Telegram alerts, 30+ metrics. Polymarketfreemium
TradesViz for Kalshi Journaling Kalshi trades from a CSV export and reading win rate, expectancy, drawdown and equity curves. Kalshifree tier$13.99/mo
TrendSpider Kalshi suite The only charting-platform integration in the space: live Kalshi odds as chart indicators. Kalshiwith sub
ArbBets 990+ matched market pairs, claims 100+ arbs daily at 2 to 8% spreads, API access. PM + K + Opinionfrom $59/mo
ArbiTrack Scanner refreshing every 3 minutes, flags 5 to 20 cent gaps across three venues. PM + K + PredictItfree tier$19/mo
DefiRate Fed odds Fed-decision lines side by side with fee-adjusted expected earnings per contract. PM + Kalshifree
event-contract-arbitrage Open-source arb scanner if you would rather run your own. K + PM + RobinhoodOSS
EventArb Free manual arb calculator with fee-adjusted risk-free setups, plus email alerts. K + PM + Robinhoodfree
PMXT Live Arbitrage Scan A terminal table of live cross-venue spreads across four venues in five commands, if you have a PMXT key. cross-venueOSS9 stars
Polymarket + Kalshi Arbitrage Finder Running a scheduled Polymarket versus Kalshi scan from Apify and getting a dataset of spreads without hosting anything. Polymarket + Kalshi$0.05
Oddpool The most direct Kalshi vs Polymarket comparison: divergence tracking with fee context, plus a real data API underneath. PM + Kalshifree tier$30/mo
Prediction Hunt Live odds from six venues in one view and one API call. 6 venuesfree core
Prediction Market Odds Comparison (Apify) A pay-per-row dataset of the same question priced on Kalshi, Polymarket and PredictIt, with the gap and whether it clears both books. cross-venuefree tier$5.00
PredScope A free Polymarket odds tracker with a Polymarket versus Kalshi fact sheet and a no-auth JSON API that refreshes every 10 minutes. Polymarket + Kalshifree
Bet Hero prediction market calculator One-screen Kalshi payout math that prints the actual fee formula it uses, so you can check its work. cross-venuefree
DefiRate calculators 13 free calculators: odds conversion, EV, fees, Kelly, hedging, parlays, Monte Carlo bankroll simulation. 10 platformsfree
Market Math Comparing every venue's fee schedule in one table and running fee-adjusted EV before a trade. cross-venuefree
OddsAssist Kalshi calcs Kalshi fee calculator with maker and taker sides (maker orders cut fees roughly 4x), plus payout calculators. Kalshifree
Prediction Markets Picks 25+ quant tools: Kelly, EV, Bayes updater, correlation-adjusted parlay edges, even an MCP server for AI assistants. cross-venuefree$14.99 pro
Start Polymarket tools Polymarket-only fee, profit and loss, EV and Kelly math, plus a country availability check, on one independent site. Polymarketfree
Adjacent News News wired to markets, with data APIs across 40K+ markets. cross-venuefree tier
Drops Odds Free Telegram alerts on Polymarket odds shifts and on every buy or sell from wallets you paste in. Polymarketfree
PolyAlertHub Whale, insider and market alerts via email and Telegram. Polymarketfree basic
Polylerts Telegram alerts when the top 0.5% of Polymarket wallets trade; community-run. Polymarketfree
Polymarket Alerts Price-change, resolution and whale alerts with iOS and Android apps, no login needed. Polymarketfree
PolyTracker Command-driven Telegram tracking of named Polymarket wallets, with a profile view of open positions and P&L inside the chat. Polymarketprice not stated
PolyTradeAlerts Paid, per-trader Telegram alerts on specific Polymarket wallets with USDC size filters and digest mode for high-frequency accounts. Polymarketfree tier$12
Prediction News Dedicated industry newsroom: regulation, funding, platform changes, market data. industryfree
Awaken Tax Crypto tax software with real Polymarket support: matches redemptions to cost basis, books losing resolutions as losses. Polymarketpaid
CoinLedger Wallet-address import of Polymarket activity into a mainstream crypto tax product with a one-time price per tax year. Polymarket + Kalshifree tier$49
COS Elite Kalshi tax calculator A CPA-built federal estimate on Kalshi winnings under four treatments, including the ordinary-income case the other calculators skip. Kalshifree
Manage Bankroll Manual cross-platform bankroll and P&L tracking spanning Kalshi, Polymarket, sportsbooks and brokers. 25 platformsfree to 50 txns$100/yr
TraderTax calculator Free 2026 calculator comparing capital, 60/40 and gambling tax treatments side by side. US taxesfree

Guides

All guides →

How to get Polymarket and Kalshi whale alertsWhat whale alert services watch on Polymarket and Kalshi: size thresholds, wallet follows, new markets, which are free, and Telegram, push and Discord delivery.How to read a Polymarket leaderboardWhat Polymarket's profit and volume leaderboards measure, how daily, weekly, monthly and all-time windows differ, why Kalshi's is opt-in, and what trackers add.Kalshi vs Polymarket taxes for US tradersWhat Kalshi's help center says it issues (1099-INT, MISC, B, DA plus a FIFO P&L statement), what Polymarket's help center leaves out, and what a tax tool needs.Prediction market arbitrage math after feesTurn a Kalshi vs Polymarket spread into a net number with each venue's documented fee formula, a worked example, and the settlement-rule risk the math skips.

Field notes

what the tool pages will not tell you

Caveat · Kalshi leaderboards

Kalshi trades are anonymous and its native leaderboard is opt-in, with users opted out by default. Every third-party "Kalshi leaderboard" is built from a small opt-in pool connected to that service, not the exchange's actual top traders. Read Kalshi copy-trading claims with that in mind.

Caveat · taxes

Kalshi issues no 1099-B for event-contract trades, Polymarket issues no US tax forms at all, and every USDC entry and exit on Polymarket is its own crypto disposal. How the IRS classifies prediction-market income is unsettled. Keep records from day one.

The gaps nobody has filled

open problems · september 2026

Cross-venue portfolio P&L

No tool automatically aggregates live positions across Kalshi and Polymarket into one P&L. Everything is manual entry or single-venue.

still open

Kalshi tax integration

Polymarket has Awaken and Blockpit; Kalshi has export-and-spreadsheet.

still open

Kalshi trader transparency

Anonymity plus an opt-in leaderboard means the Polymarket-style copy-trading economy cannot exist there yet, whatever the marketing says.

still open

Charting integrations

One TrendSpider suite; otherwise nothing connects prediction markets to mainstream charting.

still open

find the edge→size it→time it→execute

Trackers find the edge. Calculators size it. Alerts time it.

When it is time to execute, the free Kairos terminal trades Kalshi, Polymarket and Predict.fun from one book.

FAQ

What is the best free stack?

Polymarket Analytics for who is winning, Polylerts for when they move, Polysights for AI-assisted analysis, DefiRate for the math, and Kairos to execute across venues. Total cost: zero.

Is there one tool that covers Kalshi and Polymarket together?

For viewing, Oddpool and Prediction Hunt. For trading, Kairos aggregates both plus Predict.fun into one order book. For portfolio tracking, nothing automatic exists yet.

Why are there so many more Polymarket tools than Kalshi tools?

Data access. Polymarket's activity is public on-chain, so anyone can build a tracker. Kalshi trades are anonymous with an opt-in leaderboard, which caps what third parties can see and build.

Do I need paid tools?

Not to start. The free stack covers analysis, alerts, math and execution. Paid tools earn their keep in automated copy trading, always-on arb scanning, and deep historical data.